Railroad-crossing gate



(No M0888.)

0. H. CLARK.

RAILROAD CROSSING GATE. 180.807,094. Patented 081;. 28. 1884.

N. Penas, mwumugmphu. wmmgm n. 1;/

Darren Sterns 'PATENT Ormea.

OLIVER H. CLARK, OF PITTSBURG, PENNSYLVANIA.

RAILROAD-CROSSING GATE.

SPECIFECATIGN forming part of Letters Patent No. 307,094, dated October 28, 1884.

Application filed September 11, 1883. (No model.)

To co2/Z 'LU/71,0712, may concern:

Beit known that I, OLIVER H. CLARK, of Pittsburg, vin the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Railroad-Crossing Gates; and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawings, forming a, part of this specification, in which Figure l is a vertical section of two of the standards and barriers of a double gate for a railway street-crossing. Fig. 2 is a like view of the opposite gates. Fig. 3 isa vertical sec' tion of the main standard D. Fig. 4 is a view of the operating apparatus. Figs. 5 and6 are views of the sheaves.

Like letters of reference indicate like parts in each.

The principle upon which this gate is constructed is that the barriers and their respect `ive counterweights are at no time in the state that if the center of gravity is made to lie on the side of the barrier it will be horizontal, and if the center of gravity is on the side of the conntcr-weight it will be vertical. To bring the gate to either of these positions a'force must act against that which, preponderating, throws the barriers into the other of the positions named.

In the drawings, the counter-weights I J Ii L exceed in weight the barriers E F G H, and their normal position is therefore vertical. In the standards A, B, G, and D are the large groovcd wheels M, N, O, and I, which are mounted on the shafts Q R S T, which also ,sustain the barriers E F G II and their counter-weights I J K L. The barriers and the counter-weights revolve in a plane which is parallel to that of the grooved wheels or to the faces of the standards. Arope, a, is fastened t0 the wheel M, and descends on its side next the barrier E, passes around the sheave it', and under the ground in a pipe or box, a2, to the standard B, then around the sheave as to the wheel N on its side next the counterweight J; then around in one of the grooves,

f, in the wheel N to the opposite side or underneath, where it is fastened. In the second groove, o', of the wheel N lies the rope or chain c, which descends on the side next to the barrier F, passes around the sheave @Zand then extends through a box or case underground to the standard D of the opposite gate,` where it passes under the sheave c, and then' up to and around the wheel I? on the side next to the counter-weight inthe groove ct, where it is fastened.

The rope or chain bis fastened in the groove b of the wheel I), and descends on the side next to the counter-weight L, where it is conducted round the sheaves b2 b through the pipe I)4 to the wheel O in the standard C, passing over the side of the wheel next to the barrier G, and is fastened in the single groove thereof. The rope or chain d is fastened in the groove d of the wheel I), from which it descends on the side next to the barrier H, passes around the sheave d, and out of the standard through the pipe or tube d3 to any point at which it may be desired to control the movements of the gate. At this terminus of the rope or chain d is fastened the primary counter-weight q, whose weight will be sucient to equalize the weight between the barriers and their counter-weights, and thus form an equilibrium between them. There will then be two equal tensions acting in opposite directions along the rope or chain d, and to move it in either direction (or to open and close the gate) will require only a force equal to the friction exerted `by the moving parts. For the purpose of directing this force along the line of the rope or chain d, any suitable crank or lever may be used. rIlhe method of operating with the lever is pref rable, and is represented inthe drawings. A ever, r, is pivoted at r' to the frame s, which is provided with a segmental rack, s', in which the spring-pawl or catch o is engaged. The lever is secured in the line of the rope or chain d, as at frs, so that when moved along the rack it draws either' upon the gates or upon the weight q, and thus .ing of the gates.

either causes the opening or permits the clos The rope d passes around the sheave y up to the frames, and on it around the sheaves y y2 y" y* down to the weight q, which is placed between guides Q, and rises and falls therein. The throw of the lever if' will be measured by the'distance through which the counter-weight q must move to effect the opening or closing of the gates, which distance will in turn be measured by one-fourth the circumference of the wheel P in standard D, which corresponds with the arc of ninety degrees, in. which the barriers act.

The described construction is applicable for use with two standards only-as, for instance, A and B-in which case the rope or chain c would go directly to the weight q and be provided with the lever i'.

If desired, a windlass or drum operated by a crank may be used instead of the leverv'r, said windlass or drum being the mechanical equivalent of the lever and accomplishing the saine result in substantially the same way. The windlass or drinn may, if desired, be placed in the standard D, instead of outside of it, or in another standard inade especially for it.

What I claim as niy invention, and desire to secure by Letters Patent, is`

l. ln a gate i'or railroad-crossings, the cornbination, with two counterweighted oscillating barriers each having a pulley fast on its shaft, said pulleys connected by a cord or chain secured to the peripheries of the pulleys, so that the barriers shall move in unison, of the rope or chain d, secured to the periphery of one of said pulleys,the primary counter-weight q, and pivoted lever fr, substantially as and for the purposes specified.

2. In a gate for railroad-crossings, the con1- bination of two sets of oscillating counterweighted barriers, E F and G H, each barrier being provided with a pulley fast upon its shaft, and the barriers of each set connected by a rope or chain, a b, said two sets being likewise connected by a rope, c,which extends from the periphery of a pulley of one set to the periphery of a pulley of the other set, an operating rope or chain, d, provided with a primary counter-weigl1t, q, and a lever, r, substantially as and for the purposes specified.

In testimony whereof I have hereunto set my hand this 9th day of July, A. D. 1883.

OLIVER H. CLARK.

Titnessesz WV. B. CoRwiN, T. XV. BAKEWELL. 

